Stochastic character mapping of state-dependent diversification reveals the tempo of evolutionary decline in self-compatible Onagraceae lineages

A major goal of evolutionary biology is to identify key evolutionary transitions that correspond with shifts in speciation and extinction rates. Stochastic character mapping has become the primary method used to infer the timing, nature, and number of character state transitions along the branches of a phylogeny. The method is widely employed for standard substitution models of character evolution. However, current approaches cannot be used for models that specifically test the association of character state transitions with shifts in diversification rates such as state-dependent speciation and extinction (SSE) models. Here we introduce a new stochastic character mapping algorithm that overcomes these limitations, and apply it to study mating system evolution over a time-calibrated phylogeny of the plant family Onagraceae. Utilizing a hidden state SSE model we tested the association of the loss of self-incompatibility with shifts in diversification rates. Confirming long standing theory...

进化生物学的核心目标之一，是识别与物种形成和灭绝速率变化相对应的关键演化过渡事件。随机性状映射已成为推断系统发育树各分支上性状状态转变的发生时间、本质与数量的主流方法，且被广泛应用于性状演化的标准置换模型中。然而，现有方法无法用于专门检验性状状态转变与多样化速率变化之间关联的模型，例如性状依赖型物种形成与灭绝（state-dependent speciation and extinction, SSE）模型。本研究提出一种可克服上述局限的新型随机性状映射算法，并将其应用于柳叶菜科（Onagraceae）时间校准系统发育树的交配系统演化研究。本研究利用隐状态SSE模型，检验了自交不亲和性丧失与多样化速率变化之间的关联，验证了长期以来的演化理论……